In English, we can express our disappointment in very many ways. Of course, the phrases we use in any given context largely depend upon the relationship we have with the listener. For example, some phrases that are considered quite acceptable while speaking with your friends are not exactly appropriate for the workplace. This is something you need to remember when you speak.
Forms used to express disappointment
Sometimes we are disappointed with ourselves. We can express this idea using I wish I had…
I wish I had a better memory.
I wish I had silky hair.
I wish I had a better job.
I wish I had a Ferrari.
I wish I had a daughter.
Although we use a past verb form here, we are referring to the present and our disappointment with it.
The same structure can be used to express our regret over something unpleasant that happened in the past.
I wish I had listened to my dad. (= I didn’t, but no I regret it.)
I wish I had worked harder.
If only I + past simple
This structure is also used to express our disappointments.
If only I spoke German. (= I don’t speak German.)
I wish I knew him.
If only I + past perfect
This structure is used to express our regrets about past events.
If only I had listened to him.
If only I had married her.
These forms can also be used to express our disappointments with others.
If only she had listened to me.
If only she had saved some money.
I wish we had hired him. He was a more deserving candidate.
Expressing disappointment with others
To express our disappointment with others, we can use several structures.
Why didn’t you…
Why didn’t you tell me earlier?
Why didn’t you wait for me?
Why didn’t they finish on time?
How am / was I supposed to
This structure can also be used to express our disappointment or unhappiness with an existing arrangement.
How am I supposed to complete this project by Wednesday?